A look at our nearest neighbor in Space! The Moon Free powerpoints at
What is the Moon? A natural satellite One of more than 96 moons in our Solar System The only moon of the planet Earth
Location, location, location! About 384,000 km (240,000 miles) from Earth 3,468 km (2,155 miles) in diameter (about ¼ the size of Earth)
Movements of the Moon Revolution – Moon orbits the Earth every 27 1/3 days The moon rises in the east and sets in the west The moon rises and sets 50 minutes later each day Rotation – Moon turns on its axis every 27 days Same side of Moon always faces Earth
The Tidally Locked Orbit of the moon The moon is rotating with the same period around its axis as it is orbiting Earth (tidally locked). We always see the same side of the moon facing Earth.
It’s Just a Phase Moonlight is reflected sunlight Half the moon’s surface is always reflecting light From Earth we see different amounts of the Moon’s lit surface The amount seen is called a “phase” NO “DARK SIDE!!”
Terminology a.Limb – Circular edge of the moon. May be dark or illuminated b.Terminator – boundary between the illuminated disk and the dark part of the moon c.Waxing – growing d.Waning – shrinking
FULL QUARTER CRESCENT GIBBOUS FOUR MAIN SHAPES
The Phases of the Moon (I) As the moon orbits around Earth, we see different portions of the moon’s surface lit by the sun, causing the phases of the moon.
The Phases of the moon (II) New moon First Quarter Full moon Evening Sky
The Phases of the moon (III) Full moon Third Quarter New moon Morning Sky
The Orbit of the moon (I) The moon orbits Earth in a sidereal period of days days Earthmoon Fixed direction in space
The Orbit of the moon (II) The moon’s synodic period (to reach the same position relative to the sun) is days (~ 1 month). Fixed direction in space Earth moon Earth orbits around sun => Direction toward sun changes! days
Lunar Eclipses Moon moves into Earth’s shadow – this shadow darkens the Moon –Umbra –Penumbra About 2-3 per year Last up to 4 hours
Lunar Eclipses Earth’s shadow consists of a zone of full shadow, the umbra, and a zone of partial shadow, the penumbra. If the moon passes through Earth’s full shadow (umbra), we see a lunar eclipse. If the entire surface of the moon enters the umbra, the lunar eclipse is total.
A Total Lunar Eclipse (I)
A Total Lunar Eclipse (II) A total lunar eclipse can last up to 1 hour and 40 min. During a total eclipse, the moon has a faint, red glow, reflecting sunlight scattered in Earth’s atmosphere.
Solar Eclipses Moon moves between Earth and Sun Moon casts a shadow on part of the Earth Total eclipses rare – only once every 360 years from one location!
Solar Eclipses (I) The angular diameter of the moon (~ 0.5 o ) is almost exactly the same as that of the sun. This is a pure chance coincidence. The moon’s linear diameter is much smaller than that of the sun.
Solar Eclipses Due to the equal angular diameters, the moon can cover the sun completely w hen it passes in front of the sun, causing a total solar eclipse.
Total Solar Eclipse Prominences Chromosphere and Corona
Diamond Ring Effect
Earth’s and moon’s orbits are slightly elliptical: sun Earth moon (Eccentricities greatly exaggerated!) Perihelion = position closest to the sun Aphelion = position furthest away from the sun Perigee = position closest to Earth Apogee = position furthest away from Earth
Annular Solar Eclipses The angular sizes of the moon and the sun vary, depending on their distance from Earth. When Earth is near perihelion, and the moon is near apogee, we see an annular solar eclipse. Perigee Apogee Perihelion Aphelion
Almost total, annular eclipse of May 30, 1984
Approximately 1 total solar eclipse per year
Conditions for Eclipses (I) The moon’s orbit is inclined against the ecliptic by ~ 5 º. A solar eclipse can only occur if the moon passes a node near new moon. A lunar eclipse can only occur if the moon passes a node near full moon.
Partial Eclipse
Earth Moon Plane of earth’s orbit Plane of lunar orbit
Exploring the Moon 1950s to 1960s - probes Neil Armstrong First man on the Moon – July 20, 1969 Six Apollo missions ( ) –382 kg (842 lbs) rocks 12 Americans have walked on the moon
Name this phase! Full Moon What time does this phase rise and set?
Name these features. Craters Maria
Does this image show us the near side or far side of the moon? Far Side How can you tell?
Is this line the limb or terminator? Limb Terminator
Name this phase! First Quarter
Name this phase! Waxing Crescent
Does this image show the near side or the far side of the moon? Near Side
Name this phase! Waning Gibbous
Name this phase! Third Quarter
From what direction does the moon rise? The East
Name this phase! Waxing Gibbous
Name this phase! Waning Crescent
What might be happening in this image? Lunar Eclipse
Is this line the limb or the terminator? Limb
Name this phase! Look closely! Waxing Gibbous
True or False: The Far Side and the Dark Side of the moon are the same thing. False!
Name this phase! Full Moon
Name this phase! New Moon
Does the moon rise or set in the west? It sets in the west.
Name this phase! Waning Gibbous
Name this phase! Waning Crescent
Name this phase! Waning Gibbous
The Lunatic: Leesa Hubbard
Photo resources tmhttp:// tm ery-moon.html#apollohttp://nssdc.gsfc.nasa.gov/photo_gallery/photogall ery-moon.html#apollo n.htmlhttp://cass.jsc.nasa.gov/pub/research/clemen/cleme n.html ate/ ate/ pxmoon.htmlhttp://seds.lpl.arizona.edu/nineplanets/nineplanets/ pxmoon.html
More photo resources movies_index.htmlhttp:// movies_index.html pses/article_99_1.asphttp://skyandtelescope.com/observing/objects/ecli pses/article_99_1.asp em/moon_nss_ htmlhttp:// em/moon_nss_ html
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